Stick to the big names. Crypto-games, bitdice, bitvest, yolodice. Safedice doesn't have the best volume out of them, if you can aim to invest 25% in each of the 4 casinos that i've mentioned beforehand then you should be able to make a decent amount of profit over time.
BitDice are changing towards an ICO model and will not be accepting traditional bankroll investments anymore.
Apart from that, definitely stick to the big names. They have more betting volume and are less likely to make a run with your money (although that risk still exists, of course). Accordingly also stay away from newer dice sites and wait until they have proven themselves for at least 6-12 months, lest you get scammed.